Neat video from NVIDIA, showing how they can reproduce some famous Apollo 11 images from first principles with computer models and modern GPU power.
Archive for the ‘Space’ Category
Interesting set of photos of a NASA exhibition of Columbia space shuttle debris. Particularly the tile melted from beneath, showing substantial heating from inside the wing:
(From Wayne Hale’s blog)
I remember when going to Mars seemed exciting.
When I was a kid, we read books and watched TV shows about a Mars with canals and bikini-clad princesses, or Martians who wanted to invade the Earth in tripods or by controlling cloned humans.
But, even by then, science already knew that most of those stories were false. The earliest Martian flybys told us that the planet was too cold and the atmosphere too thin to support life much beyond primitive plants. Then, not long after, the Viking landers closed even that loophole when they showed the surface to be an arid desert.
Yet, much of the spaceflight community is still following the old script, first humans land on the Moon, then on Mars. The script made sense when those bikini-clad princesses needed to be rescued from Martian tripods, but not now Mars is just a rock. Any useful resources there are likely to be retrieved more easily from asteroids and moons with much lower gravity where you can use propulsion more efficient than chemical rockets.
It just makes no sense as anything other than an Apollo-style flag-waving exercise. We’d do far better to begin by colonising asteroids whose materials can be used to build more optimal habitats in free space.
Here’s an interesting way to simulate Mars gravity:
I’ve been puzzling over this myself recently as I try to finish my first SF novel; it’s set on Vesta, where gravity is approximately 4% of that on Earth. That’s enough to be annoying but not enough to be useful.
Walking relies on gravity, leaning forward to move your legs, so on very low gravity worlds it would be problematic. A bounding run should work, but could be difficult to control.
Wheels would work, but can only put as much power down as the friction between wheel and ground allows. Since the gravity is much lower, the friction will also be much lower, so you won’t be able to accelerate or brake rapidly.
A railway — probably a monorail — seems potentially effective; if the wheels are forced against the rail, there should be enough grip to allow rapid acceleration and deceleration.
Hovercraft seem sensible, since little power would be required to counteract the low weight of the vehicle, and then it can be propelled by ducted fans or similar as though it was in microgravity in free space.
Moving walkways could work, and would likely be a sensible approach for speeds between slow walk and bounding run. If friction between feet and walkway isn’t enough, a railing could pass the force through, even if it would probably be uncomfortable.
More high-tech, some kind of nano-assisted material for soles and tires could help them cling to the ground and at least help with the friction problems.
I’m still trying to think of a sensible solution for movement on these kind of worlds which doesn’t come with a large number of downsides.
Interesting documentary about Skylon:
However, I think it underestimates the fundamental problem with Skylon. It’s very clever, but suffers from what you might call ‘Apollo Syndrome’; it’s very much an all or nothing design which needs huge up-front investment with no guarantee of success. Without that multi-billion dollar investment you have nothing of use, which effectively limits it to a government program as few companies can afford to take that kind of risk.
SpaceX, for example, expects to reduce launch costs to Skylon levels when they have a fully-reusable Falcon, but they don’t need to invest vast amounts of money to do because they can make money from the expendable Falcon first and work toward the low-cost reusable design. The best suggestion I’ve seen for Skylon is to use it as a hypersonic airliner, but that still requires doing most of the work and there’s no proven market.
So will it ever fly? I’d like to think so, but I honestly can’t see how they’ll convince the people who have enough money to give it to them.
Neil Armstrong died, but by now you probably know.
As I said elsewhere, the sad part is not just that the first man to walk on the moon has died, but before long we may be in a world where no man alive has walked on the moon. What a huge step backward for the human race.
Is in the middle of Mars entry. Or, more precisely, has already either landed or crashed and we’re just waiting to find out which.
We’ll know in a few minutes…
In just over five hours we find out whether Curiosity can land safely or it’s a complete disaster. Let’s keep our fingers crossed:
Some great pictures of Enterprise on its way to the museum and Explorer heading for display elsewhere.
This something I posted elsewhere as a response to a comment on a discussion about aliens which mentioned that the distances between stars in the galaxy is very large and difficult to cross.
The real problem is that the distances within a galaxy are too short.
We pretty much know how to travel between stars at 1-10% of the speed of light. There’s probably a few centuries of detailed engineering work to get from here to there, but the physics works and doesn’t require impossible amounts of energy. At the high end of the scale we can colonise the entire galaxy in a million years, at the low end in ten million.
So if expansionist technological societies typically evolve more than ten million years apart, the first one will take over the galaxy before the second has a chance to evolve.
Someone has to be first, and right now it looks like that’s us; if someone else was out there and even a few tens of thousand years ahead of us we should be able to see evidence of their existence from here. I could quite imagine that they have evolved and then wiped themselves out or gone introverted rather than spread across the galaxy, but that makes them just a footnote in galactic history.
We can see oddities in other galaxies which could be signs of engineering on a massive scale. But intergalactic travel at even 10% of the speed of light would take a very long time.
Neat picture of the Dragon over Namibia before docking with ISS:
And another of the inside of the Dragon docked at ISS:
The Dragon is safely in space, so let’s hope it gets to the space station and proves it’s a viable means of supply.
We did try to see the eclipse here, but most of the time the sun was behind a cloud and when it was visible we didn’t have anything dark enough to look through without diffusing the image so much that we couldn’t see the sun anyway.
I’ll have to make do with a couple of pictures I took of the near-total eclipse in England a few years ago.
Actually, here’s the lunar eclipse we had here a couple of years back:
All three of these are stills from my camcorders, which explains some of the image artifacts.
Got up this morning hoping to see the Dragon in orbit, but there was a last-minute abort due to unexpected readings from the engine. When you’re making a test flight it’s better to abort than risk the entire mission, hopefully the delay will only be a few days.
SpaceX are finally preparing for their first Dragon flight to ISS in a few hours; hopefully it will all go well, I don’t think I can stay up late enough to watch.
It may not be as impressive as a space shuttle launch, but right now they’re the best hope for cheap access to space in the next couple of decades.
I missed it, but apparently the Endeavour space shuttle was powered down on Friday, marking the absolute end of the shuttle program:
I’ve seen several shuttle launches, many of them from the VIP site at the Kennedy Space Centre, including Endeavour’s first flight. It’s well past time that they were retired for a cheaper and more reliable replacement, but seeing the last of them turned off is still a sad day.
Oh, here’s the view from said VIP site:
While it may take a little too much from 2001, it does have some interesting ideas:
http://www.playboy.com/magazine/the-playboy-club-in-space (possibly NSFW images)